The present invention relates to a wear-resistant alloy.
In overhead camshaft internal combustion engines a valve rocker arm such as 1 shown in FIG. 1 is often incorporated for transmitting the rotational movement of a camshaft to an intake or exhaust valve so as to reciprocate it. The valve rocker arm has a pad face 2 at its one end portion which contacts the cam lead face of the camshaft and is driven thereby. Therefore it is desired that the pad face should have high wear resistance and tenacity.
Because of this, there have been proposed various special materials for use as the pad face, or various surface treatments to be applied to the surface of the pad face, such as chromium plating, chilling of cast iron, nitriding, etc. However, these conventional treatments have not yet provided satisfactory results. Chromium plating is liable to exfoliate in use, while chilling of cast iron and nitriding are not satisfactory with regard to wear resistance.
In recent years, it has become known to spray wear resistant alloy such as stellite and self-fluxing alloy by the spray-fuse process onto the pad face, or to make the pad face portion out of a low cast iron including small amounts of Cr, Mo, etc.. However, these conventional materials appear to be unable to match up to ever-increasing requirements for the pad faces of valve rocker arms.